Changes occurring in vegetable oils composition due to microwave heating

Authors

  • Minar M. Hassanein National Research Centre, Fats and Oils Dept., Dokki, Cairo
  • Safinaz M. El-Shami National Research Centre, Fats and Oils Dept., Dokki, Cairo
  • M. Hassan El-Mallah National Research Centre, Fats and Oils Dept., Dokki, Cairo

DOI:

https://doi.org/10.3989/gya.2003.v54.i4.219

Keywords:

Chemical changes, Heating, Microwave, Vegetable oil

Abstract


The effect of microwave heating on three vegetable oils having different lipid compositions was studied. Sunflower, soybean and peanut oils in comparison with oil admixture of soybean and peanut oil (1:1, w/w), were selected for this study. Each oil was heated for 2, 4, 6, 8, 10, 12, 15 and 18 minutes in microwave oven. Peroxide value, free acidity and colour absorbance (at 420 nm) were proportionally increasing with the increase of heating period. Colour absorption threw light on the formation of browning products arising from phospholipids during microwave heating. Total tocopherol contents were determined by preparative thin layer chromatography, whereas the fatty acid compositions and formed epoxy acid were analyzed by capillary gas liquid chromatography. The formed conjugated dienes and trienes were determined by UV spectrophotometry. It was found that the total tocopherols of the microwave heated oils, decreased depending on the type of the predominating tocopherols. Also a relation of peroxide formation, during microwave heating, with changes in total tocopherol composition was discussed. It was found that polyunsaturated fatty acids generally decreased by increasing the heating period. The results obtained from the heated oil admixture helped interpret the results obtained from other heated individual oils.

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Published

2003-12-30

How to Cite

1.
Hassanein MM, El-Shami SM, Hassan El-Mallah M. Changes occurring in vegetable oils composition due to microwave heating. grasasaceites [Internet]. 2003Dec.30 [cited 2022Dec.7];54(4):343-9. Available from: https://grasasyaceites.revistas.csic.es/index.php/grasasyaceites/article/view/219

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Section

Research